The invention relates to a spring for retaining spring for producing an articulated connection of a wiper blade to a wiper arm of a vehicle, in which the retaining spring has a first connecting means for making a first connection to a retaining element of the wiper blade and a second connecting means for making a second connection to a carrier element of the wiper arm.
The invention also relates to a wiper system comprising a wiper arm and a wiper blade, secured to it in articulated fashion, with the interposition of a retaining spring.
Retaining springs and wiper systems of these generic types are known. In particular, retaining springs are known that are received by an associated end, which is U-shaped in longitudinal section, of the wiper arm in the articulated connection region, thus producing a snap connection. Articulated connections embodied in this way are difficult to mount and relatively hard to manipulate with regard to securing a wiper blade to the corresponding wiper arm. Removing the wiper blade from the wiper arm also entails relatively major effort, possibly requiring the use of special aids in manipulation.
The retaining spring of the invention is characterized in that the articulated connection can be produced by means of the first and the second connecting means, in the operating position of the retaining spring, in a mounting direction that is essentially perpendicular to an operating plane of the wiper blade. As a result, the articulated connection can be produced in a way that is especially easy to mount and manipulate, since during the entire mounting process the retaining spring can remain in the operating position with respect to the wiper blade and the wiper arm and thus need not assume any additional, special mounting positions. The mounting can advantageously be done in a single direction, which is perpendicular to the operating plane of the wiper blade. This is accordingly a direction which in the operating position of the wiper blade leads essentially at a right angle to and away from a surface of a window of a vehicle. This mounting direction is especially favorable in terms of manipulation, since the person mounting a wiper blade on a wiper arm does not have to provide any special rotary motions of the retaining spring in the articulation region of the wiper blade; instead, rectilinear motions of the retaining spring, or of the wiper blade with the premounted retaining spring, and/or of the wiper arm, maintaining the operating position of the retaining spring, suffice to produce a complete and reliable articulated connection between the wiper blade and the wiper arm with the interposition of the retaining spring.
Advantageously, the first connecting means is embodied as a first seat accessible from outside, and the second connecting means is embodied as a second seat accessible from outside. Because the two connecting means of the retaining spring are each embodied as a seat accessible from outside, it is possible to achieve an easily mounted snap connection of the wiper blade and of the wiper arm with the retaining spring disposed between them; the mounting direction in each case is always essentially perpendicular to the operating plane of the wiper blade. Since the articulated connection region of the wiper blade and of the wiper arm is preferably of metal in each case, and the retaining spring is advantageously of a suitable plastic material, it is advantageous, in particular from a production standpoint, to embody the first and second connecting means each as a seat, to make designs of the wiper blade and the wiper arm possible that are structurally relatively simple; this allows the production of an easily mounted, reliable articulated connection.
Preferably, the second seat is embodied as a receptacle unit for the carrier element, and the retaining spring has a stop means that limits the reception of the carrier element. Embodying the second seat as a receptacle unit makes it possible to design the carrier element relatively simply, for instance as a rib that protrudes from the wiper arm and that can be introduced in an especially easily mounted way into the second seat in the mounting direction. Because a stop means is furnished on the retaining spring, it is possible in an easily mounted and reliable way to achieve a correct reception of the carrier element in the second seat.
Advantageously, the stop means is embodied as a structured surface outside the receptacle unit. Because the stop means is embodied outside the receptacle unit, it is not in direct operative connection with the carrier element but instead can be put into contact with a corresponding counterpart face of the wiper arm. The carrier element, embodied for instance as a rib, merely has a carrier function; the introduction length of the carrier element (rib) to be introduced into the second seat defines a separate stop means. This prevents damage to the second seat from the carrier element in the mounting direction, since the stop means always assures correct positioning of the carrier element in the receptacle unit. A collision between the carrier element and the receptacle unit in the mounting direction is thus avoided. By means of a geometric structuring of the surface of the retaining spring acting as a stop means, it is possible, for instance by means of beadlike protrusions, to embody a relatively large effective surface area as a stop face, with relatively slight frictional contact between the retaining spring and the wiper arm.
Advantageously, the first connection and the second connection are embodied as an elastic and releasable snap connection. An elastic and releasable snap connection is especially easy to mount and can be achieved especially fast.
It is especially advantageous that both the first and the second snap connection can be achieved in a single mounting direction.
In a preferred embodiment, the first seat is essentially U-shaped in longitudinal section, and the retaining element of the wiper blade is embodied as a rivet.
A first seat embodied as U-shaped in longitudinal section is simple to achieve from a production standpoint and at the same time has the requisite stability for a reliable snap connection to the retaining element of the wiper blade. Such a snap connection is advantageously effected with a retaining element embodied as a rivet. Such wiper blades, which have a middle bracket with a rivet (rolling rivet) as a retaining element, can be manufactured relatively inexpensively and are relatively easy to install.
Advantageously, the retaining spring is embodied in one piece. By means of a one-piece retaining spring, the number of parts to be mounted in order to produce the articulated connection is reduced to a minimum, that is, to three construction parts (the wiper blade, retaining spring, and wiper arm). From a production standpoint, a retaining spring that can be made from a suitable plastic material is relatively simple to achieve in the form of a one-piece construction element.
Preferably, the receptacle unit is embodied as two receptacles, which are essentially U-shaped in longitudinal section and between which the first seat is disposed. In this way, it is possible to create a force-symmetrical articulated connection, in which during the mounting, no or virtually no forces that generate torque and/or bending moment are introduced into the retaining spring.
Advantageously, the walls of the first and second seat in longitudinal section together describe essentially the shape of a W, and the access openings of the two receptacles forming the second seat are located in the opposite direction with respect to the opening of the first seat. Such a retaining spring, embodied essentially axially symmetrically, makes a self-securing disposition of the retaining element of the wiper blade and of the carrier element of the wiper arm in the retaining spring possible. This can be ascribed to the fact that an external pressure force, acting in the mounting direction and oriented inward relative to the retaining spring, presses the retaining element and the carrier element into the associated seat and thus exerts a self-securing influence on the articulated connection. Especially in the operating position of the wiper system, such a pressure force is permanently transmitted to the retaining spring from the wiper arm and the wiper blade resting on a vehicle window. Thus no additional separate locking elements are necessary to produce a reliable articulated connection.
Advantageously, the walls of the first seat are elastically pivotable relative to one another. By means of an elastic pivotability of the walls of the first seat, a snap connection of the retaining element in the first seat can be attained that is easy to mount and that ensues automatically when mounting force is suitably brought to bear in the mounting direction.
In a preferred embodiment, the receptacle unit is provided with elastic snap means, by means of which a nonpositive connection to the carrier element of the wiper arm can be produced. The embodiment of such elastic snap means on the receptacle unit makes a reliable, easily mounted connection of the carrier element to the retaining spring possible. The snapping and unsnapping force of the elastic snap means that has to be overcome can advantageously be adapted to a given application by suitable structural provisions.
Advantageously, on each of its free longitudinal ends, the retaining spring has one guide portion, which is essentially U-shaped in cross section and which can be slipped from outside onto a middle bracket of the wiper blade. A guide portion embodied in this way on the respective longitudinal end of the retaining spring assures fast, stable mounting of the retaining spring on the middle bracket of the wiper blade. Thus not only is a snap connection created between the retaining element (rivet) of the wiper blade and the retaining spring, but in addition a touch contact, which may ensue with friction, is established between the corresponding surfaces of the guide portions and of the middle bracket of the wiper blade. Once again, when the guide portion of essentially U-shaped cross section is slipped on, the frictional forces can be operative, by means of suitable structuring of the contact surface, for instance by the embodiment of beads on the inside surfaces of the guide portion, over a relatively wide range, and their magnitude can be adapted to the given application. With regard to the frictional forces occurring upon mounting between the respective guide portion and the middle bracket of the wiper blade, a force-symmetrical design of the retaining spring is advantageously provided.
In a preferred embodiment, the snap means are embodied as a profile that is open toward the outside and is elastically compressible from outside. Designing the snap means as an open profile prevents the establishment of excessive prestressing (tensile and/or compressive stress) in the snap means in the state of repose, or in other words after the articulated connection has been produced. Such prestresses, occurring in the form of compressive and/or tensile stresses, can come about from the influence of weathering (ambient temperature), for instance.
In a further embodiment, the snap means are embodied as a profile that is closed toward the outside and is elastically compressible from outside. The snap means, embodied as a profile that is closed toward the outside, are characterized by a relatively high stability. Furthermore, a snap means designed as a profile closed off toward the outside makes a compact construction of the retaining spring that is free of outer edges possible.
The wiper system of the invention is characterized in that in the region of the articulated connection, the wiper arm is provided with an opening, from which at least one and in particular two spaced-apart ribs protrude inward as a carrier element and are received in the associated receptacle, which is U-shaped in longitudinal section, of the second seat, forming an elastic snap connection by the snap means of the retaining spring. A wiper arm with one opening and two inward-protruding ribs as a carrier element is relatively simple to make from a manufacturing standpoint. Furthermore, the carrier element embodied as two ribs makes it especially easy from a mounting standpoint to produce the articulated connection, since the two spaced-apart ribs merely need to be introduced in the mounting direction into the receptacle, which is U-shaped in longitudinal section, of the second seat, forming an elastic snap connection, by means of the snap means that enter into operative connection with the ribs. Thus no rotary or positioning motions of the retaining spring relative to the wiper arm and/or the wiper blade are necessary for producing an effective, correct articulated connection between the wiper arm and the wiper blade.
Advantageously, the wiper arm, at least in the region of the articulated connection, is embodied essentially as a U-shaped profile in cross section. Embodying the wiper arm in the region of the articulated connection as a profile that is U-shaped in cross section on the one hand forms a shield of the ribs protruding inward into the U-shaped profile and thus lessens the risk of injury to the person making the articulated connection during mounting or unmounting of the wiper blade. On the other hand, given a suitable design of the flanks of the U-shaped profile of the wiper arm in the region of the articulated connection, it is also possible to shield the snap connection of the retaining element (rivet) of the wiper blade in the first seat of the retaining spring laterally in such a way that the connection between the retaining spring and the retaining element of the wiper blade is not apparent from outside. A retaining spring shielded in this way is additionally protected against external influences that can undesirably undo the snap connection between the retaining element of the wiper blade and the retaining spring.
Preferably, the snap means, after the snap connection has been made, are accessible from outside through the opening of the wiper arm. Snap means that are accessible from outside are advantageous since they enable problem-free release of the articulated connection and replacement of an old, worn wiper blade with a new wiper blade. This kind of accessibility of the snap means thus assures easily manipulated unmounting of a wiper blade or of the retaining spring from the wiper arm.
In a preferred embodiment, the ribs are each provided with two spaced-apart chamfers, and one of the two chamfers is embodied on one free end of the corresponding rib, and the second chamfer is provided in the region of the snap means operatively connected to it. The ribs can be provided with chamfers in an especially simple way from a production standpoint. These chamfers enable a fast and reliable connection of a wiper arm to the retaining spring, forming a snap connection. The first chamfer, embodied on one free end of the corresponding rib, assures an elastic deformation of the corresponding snap connection that widens the opening of the second seat, in order to guarantee an unhindered introduction of the associated rib into the receptacle, which is U-shaped in longitudinal section, of the second seat. The second chamfer, after the rib has been introduced completely into the receptacle, comes into operative contact with the associated snap means in such a way that an automatically ensuing snap connection occurs, brought about by the operative elastic restoring force of the snap means. The snap connection between the snap means and the rib is thus effected by an automatic, elastic back-deformation of the corresponding snap means, as a result of which the opening spacing is reduced. During the production of the second connection, the snap means remains continuously in touch contact with the rib, whose two chamfers generate the elastic motion of the corresponding snap means while the rib is being introduced into the second seat.
Advantageously, the ribs are in external touch contact with the associated wall of the first seat which is essentially U-shaped in longitudinal section. To allow the retaining spring to be embodied as compactly as possible, the first and second seat are disposed in the shape of a W relative to one another, so that the walls of the first, U-shaped, centrally disposed seat simultaneously represent a corresponding wall of one of the two laterally disposed seats that are also U-shaped in longitudinal section. Because of the touch contact of the ribs with the outer surface of a corresponding wall of the first seat, where the outer surface of the first seat represents a corresponding inner surface of the second seat, this originally elastically bendable wall of the U-shaped first seat is reliably kept in position once the articulated connection has been made, so that the snap connection between the retaining element (rivet) of the wiper blade and the first seat is stabilized.
Preferably, the flanks of the wiper arm, which is embodied as essentially a U-shaped profile in cross section, cover the connection between the wiper blade and the retaining spring in such a way as to make it invisible from outside. This enables the use of a wiper blade whose retaining element is embodied as a rivet (rolling rivet). A wiper blade with a rivet as a retaining element is simple to make from a production standpoint and is relatively inexpensive. By means of the flanks of the profile, which is U-shaped in cross section, of the wiper arm, the entire articulated connection is shielded laterally, so that in the operating position of the wiper system, it is advantageously not apparent from outside which type of retaining element the associated wiper blade is provided with.
In a preferred embodiment, in the connection region the wiper blade is provided with two spaced-apart openings, between which the retaining element is disposed and through which the walls of the receptacle unit of the retaining spring protrude. The two spaced-apart openings of the wiper blade advantageously make the walls of the receptacle unit of the retaining spring accessible from outside. This makes it possible, by transmission of a corresponding external compressive force on the walls of the receptacle unit of the retaining spring after the articulated connection has been made and by simultaneously restraining the wiper blade, to undo the snap connection between the retaining element (rivet) of the wiper blade in the first seat of the retaining spring. This kind of undoing of the snap connection between the retaining element (rivet) and the first seat of the retaining spring is possible, however, only if beforehand the snap connection between the two retaining ribs and the elastic snap means has been undone, since when the ribs are disposed in the receptacles, the ribs, because of the external touch contact with the associated walls of the first seat that is U-shaped in longitudinal section prevent an elastic motion or bending of the walls of the first seat that releases the retaining element of the wiper blade.
Further advantageous features of the invention will become apparent from the description.